FDA Approves Gleevec for Use in Inoperable or Metastatic GISTs

FDA Approves Gleevec for Use in Inoperable or Metastatic GISTs

ROCKVILLE, MarylandThe Food and Drug Administration (FDA) has approved
the use of Gleevec (imatinib mesylate, Novartis) for the treatment of
c-kit-positive inoperable and metastatic malignant gastrointestinal stromal
tumors (GISTs).

The FDA granted marketing approval on the basis of objective response to
Gleevec that was established in a phase II study of 147 GIST patients, 38% of
whom showed a partial response to treatment with the oral medication. Gleevec
was originally approved on May 10, 2001, for the treatment of three stages of
chronic myeloid leukemia (CML)myeloid blast crisis, accelerated, and
chronic.

"This is the first time we have seen such encouraging results in a drug
used to combat GISTs," said George Demetri, MD, of the Dana-Farber Cancer
Institute, who led the open-label, international study. "Gleevec
represents the most major advance to date for a patient population that has had
no alternative other than surgery for treating this resistant disease."

GISTs are the most common form of gastrointestinal tract sarcoma and affect
an estimated 2,000 to 5,000 people in the United States. Patients with
unresectable or metastatic GISTs have been considered incurable and essentially
untreat-able, with a median survival of about 10 to 12 months.

In the study reviewed by the FDA, researchers randomized 147 patients to
receive either 400 mg or 600 mg of Gleevec daily for up to 24 months. Although
none of the participants had a complete response to the oral medication, 56
patients33% of the 400-mg arm and 43% of the 600-mg grouphad a partial
response, defined as a reduction in tumor size of 50% or more. None of the
patients in the study had been followed long enough to determine a meaningful
response duration.

Most patients experienced an adverse side effect at least once while taking
Gleevec, but most of the events were mild or modest in severity.